Thanks! Interesting!
A Christian kingdom in Sudan between 700 and 1400! This was something I did not know.
Might have contributed to the legends of Prester John...
I’ve always been fascinated by the ‘underground’ churches in Lalibela, Ethiopia:
https://www.discovery.com/exploration/Ethiopian-Churches
https://en.wikipedia.org/wiki/Lalibela
A large portion of Africa especially north and east Africa was Christian until the Mohammedans came through. Some places managed to hold out like Ethiopia (Axiem) and Makuria (Meroe).